Blank forming press



y 957 J. R. BAUMGARTNER 2,798,417

BLANK FORMING PRESS Filed Dec. 25, 1954 2 Sheets-Sheet l A-r-roauavs J. R. BAUMGARTNER 2,798,41?

BLANK FORMING PRESS July 9; 1957 Filed Dec. 23, 1954 2 Sheets-Sheet 2 "7 v I v 50 3/ 1 24, AL lhL.

B JNVENTOR. BY. 1

A-r-roauavs United States Patent 2,798,417 BLANK FORMING PRESS John R. Baumgartner, Milwaukee, Wis.

Application December 23, 1954, Serial No. 477,181

2 Claims. (c1. 93-583) The invention relates to presses and more particularly to a carton or container blank forming press.

In presses of the above mentioned type, sheet or web paper stock fed into the press is operated upon by a set of blank forming members or dies, one carried by thefixed platen and the other carried by the reciprocating platen of the press. One of the dies is a plate equipped with cutting knives and creasing members, and the other is a counterplate having reliefs cooperating with said creasing members and surfaces forming backing portions for said knives. Each blank forming member is mounted in a chase carried by its associated platen. Where the blanks to be formed are of considerable area, it has been found that the blank forming member mounted on the upper press platen due to the action of gravity sags downwardly toward the center from its regions of anchorage in the chase. This sagging effect of the blank forming member is objectionable because it interferes with the proper registry of the blank forming members, it also prevents the use of a small working clearance between these members and hence necessitates a longer press stroke, and it also causes vibrations of the sagging plate which if it carries the knives and creasers tends to loosen these members. The object of the invention is to provide a simple and effective means for preventing sagging of the blank forming member used in the upper press platen so that this member will be held up against the platen over substantially its entire area and thus obviate the objections above mentioned. More particularly, the invention consists in providing a series of magnets, preferably permanent magnets in the upper press platen in attractive association with the metal plate surface of the forming member to hold this member firmly in contact with the platen and thereby prevent sagging due to gravity.

The invention further consists in the several features hereinafter described and more particularly defined by claims at the conclusion hereof.

In the drawings:

Fig. 1 is a side elevation view of a blanking and creasing press equipped with the invention;

Fig. 2 is a detailed vertical sectional view taken on the line 22 of Fig. 1;

Fig. 3 is a detailed plan view of the face of the upper platen, parts being broken away;

Fig. 4 is a detailed vertical sectional view taken on the line 4-4 of Fig. 1, parts being broken away;

Fig. 5 is a view similar to Fig. 4 showing the conventional arrangement;

Fig. 6 is a detailed vertical sectional view taken on the line 6-6 of Fig. 3;

Fig. 7 is a detailed vertical sectional view taken on the line 77 of Fig. 6;

Fig. 8 is a bottom plan view of the parts shown in Fig. 6.

Referring to Fig. l, the numeral 9 designates the base of a press frame provided with spaced uprights 10 carrying the upper fixed press platen 11. A movable platen 12 is slidably mounted on the uprights 10 and reciprocated in any suitable manner as by connecting rods 13 operatively connecting said platen with eccentric carrying shafts 14 that are connected together by gears 15, one of these gears meshing with a power driven gear 16.

The upper surface of the platen 12 has a suitable chase or frame 17 in which one of the blank forming members 18, such as the usual counterplate, is clamped by a suitable releasable clamp C.

The lower surface of the platen 11 has a suitable chase or frame 19 in which the other of the blank forming members 20, such as the usual cutting and creasing member, is clamped by another claimp C.

While the invention has been shown in connection with a cutting and creasing member as the upper or suspended member, it is to be understood that this member may be the counterplate.

Referring to Fig. 5, I have shown the sagging condition of the metal plate portion of the forming member 20 as frequently occurs when said member is attached to the lower face of the upper press platen. This sagging or deflection of the plate as indicated at 21 is greatest at the central portion of the plate and is caused by the weight of that portion of the plate which is suspended between its edge portions clamped to the chase. As a result of this sagging, there is a tendency of this unsupported intermediate portion of the plate to bounce or vibrate during the operation of the press, and this is especially objectionable where the forming member carries the cutters and creasers as these may become loosened from their settings. The sagging also introduces an unwanted clearance between the forming members which necessitates a longer stroke for the movable platen, and for eflicient operation the clearance between the die members should be a minimum. The sagging or deflection of the plate may also prevent proper registry of the creasers with the reliefs in the counterplate.

To prevent this sagging action of the blank forming member I have mounted a series of magnets, preferably permanent magnets 22 in the bottom face of the upper press platen 11 whose pole faces are in attractive relation with the rear surface 23 of the blank forming member and act to firmly hold this member in its intermediate area firmly against the surface of the platen. In Figs. 2 and 3 I have shown five of these magnets, distributed relative to the plate as shown in Fig. 2 to secure the desired results though other arrangements, of course, may be made depending upon the plate dimensions.

Referring to Figs. 6 to 8, each magnet 22 is formed from a cylindrical bar of suitable permanent magnetic material such as Alnico. This bar has concentric axial- 1y alined bores 24 and 25 and a slot 26 across the bore 25 to provide north and south poles.

Each bar is encased in a non-magnetic housing formed by a sleeve 27 and an annular plate 28 of suitable nonmagnetic material, such as stainless steel. The bottom face of the press platen 11 is bored out to receive the abore described housing and also has a threaded bore 29 alined with the bores 24 and 25. Each magnet is clamped in its housing by a stainless steel bolt 30 whose shank passes through the bore 24, the hole in the plate 28 and engages at its threaded end with the bore 29. A lock washer 31 of suitable non-magnetic material may be interposed between the head of the bolt and the shoulder formed between the bores 24 and 25. The face of the sleeve 27 is flush with the surface of the upper platen, and the face of the magnet 22 is either flush with the face of the platen or about one-thousandth of an inch below this surface.

With the magnets disposed as indicated in Fig. 2 and mounted as shown in Figs. 6 and 7, when the blank forming member 20 is pushed into its chase 19 and locked by the clamp C, the magnets 22 exert a powerful attrac- 3 tive force on the plateportion of said member which takes out the sag of the intermediate portion so that the member lies substantially flat against the lower face of the upper platen as shown in Fig. 4.

I desire it to be understood that this invention is not to be limited to any particular form or arrangement of parts except in so far as such limitations are included in the appended claims.

What I claim as my invention is: I

1. In a blank forming press having an upper platen and a blank forming member secured at its side edges to the lower face of said platen, means for preventing sagging of the intermediate portion of said member-comprising a series of segregated permanent magnets mounted in said platen in direct attractive relation with said portion of said member. I

2. The structure as defined in claim 1 wherein the permanent magnets are in the form of centrally bored cylinders having slotted lower ends mounted in non-magnetic housings inset in said platen and clamped to the platen by non-magnetic bolts mounted in the bored portions of said cylinders.

References Cited in the file of this patent UNITED STATES PATENTS 1,221,815 Adams Apr. 10, 1917 1,289,679 Craig Dec. 31, 1918 1,939,681 Fleming Dec. 19, 1933 1,961,797 Smith June 5, 1934 2,032,047 Burke Feb. 25, 1936 

